Bug 1296622 - Intermittent dom/tests/mochitest/chrome/test_focus.xul, disabled on linux opt. r=gbrown

MozReview-Commit-ID: FGG9Z3T8BYC

dom/tests/mochitest/chrome/chrome.ini

@@ -54,6 +54,7 @@ skip-if = os != 'mac' || os_version == '10.6'
 [test_cyclecollector.xul]
 [test_docshell_swap.xul]
 [test_focus.xul]
+skip-if = os == 'linux' && !debug # bug 1296622
 [test_focus_docnav.xul]
 [test_focus_switchbinding.xul]
 [test_focused_link_scroll.xul]